Implement indentation of elements when no selection is active in composer.
Bug #702442 - [webkit-composer] Changing indent makes paragraph style "Blockquote"

We have to look on what type of blockquote we have as parent and
afterwards decide if we are in indented paragraph.
Implement changing of block format when there is no active selection in composer.
Replace C cast with macro.
Fix of bug when some HTML elements were not quoted.